Can someone help with what I'm missing, or help capturing what the error actually is? I am not even doing anything, like connecting to a DB. I just am running a bare bones perl script with the 'use DBD::ODBC' in it.

I had a similar problem with an Oracle database: the script would run fine when launched manually from my account but would fail when launched vie the crontab. It turned out that the problem did not have to do with Perl (I reproduced it with a shell script and sqlplus commands), but with some environment variables needed to be able to connect to the Oracle database, which were not set for the root account. You might have a similar problem.